Trunking YuccaTrunking Yucca
Most people are accustomed to seeing Yuccas around Niagara, but those are Yucca fillimentosa which does not grow a trunk. Trunking Yuccas grow a trunk at the rate of about 2″ per year. Their key to survival is well-drained soil; they will tolerate very cold winters as long as the soil is not wet.  If they are in an exposed area during the winter, they should be covered up to keep snow out of the crown (this can lead to rot).

Varieties:
Yucca faxoniana
Yucca rostrata
Yucca linearfolia